1. Field of the Invention
The present invention relates generally to an apparatus and a method for cleaning and re-inking ribbons, and more particularly, to such apparatus employing a rotating brush for cleaning and treating a used printer ribbon prior to re-inking in such a manner as to extend the usable lifetime of the ribbon.
2. Description of the Prior Art
Heretofore, line printers such as those utilized in conjunction with computers and terminals in recent years have become widely used, not only as a tool for science and engineering, but also as a vital part of many business operations. Such line printers of the computer, terminal, etc., type utilize ribbons, typically fabricated from nylon cloth, silk or the like as a source of ink for the original or top copy on the printer. Conventional computer printer ribbons of the type described are relatively expensive, and, for example, generally cost between $13 and $30. Such ribbons provide between five and six million lines of printing before the original ink supply is depleted. However, since today's line printers produce in excess of 1100 lines print per minute, the ribbons must be changed frequently where the printer is in continuous use. As a result of the high cost of new printer ribbons, machines have been developed for re-inking or rejuvenating used printer ribbons.
At present, the standard machine for re-inking printer ribbons is one manufactured by the Burroughs Corporation. This machine employs a mechanism for re-inking the ribbon that includes an ink roller in contact with a tray filled with ink, a metering roller mounted parallel to the inking roller for metering ink onto the inking roller and a pressure roller mounted above the inking roller such that when the ribbon is disposed between the inking roller and the pressure roller the pressure roller is forced toward the inking roller causing ink to be applied to the ribbon. It has been found that the machine has a tendency to under-ink the ribbon. Hence, documents printed with such ribbons typically have a print quality that lacks the uniformity and degree of darkness necessary in most computer printout operations.
In addition to the above disadvantage, the machine does not employ any means for cleaning the used ribbon prior to re-inking or any mechanism for detecting defects, such as holes or thin spots in the ribbon. In this respect, when ribbons are not cleaned prior to being re-inked, dried ink, gum, lint, bits of paper, dirt, dust, and the like build up on the ribbon. This residue tends to flake off and carry with it the new ink supplied thereover which further deteriorates print quality. This becomes more of a problem when recycled paper is used to fabricate the printing paper.
Another device for re-inking a computer ribbon includes an ironing means for ironing and applying heat to a ribbon passing from a feed spindle to a take-up spindle before the ribbon is inked. This ironing means is relatively slow and complex and as a result, the device has not been accepted in the marketplace.
Yet another device for cleaning and re-inking a typewriter ribbon is a hand-operated one which includes two hand cranks, two rotatable brushes and an ink bath. The typewriter ribbon passes between the brushes which brush solid particles from the ribbon and down into the bath so as to become saturated with ink. Because of the size of the gears which drive the brushes, the brushes rotate at a much greater angular velocity than the cranks, thereby causing the dust, dirt and other solid foreign particles to be swept in front of the brushes. A disadvantage of the device is that the foreign particles may be reintroduced into the typewriter ribbon, either prior to or after re-inking. In addition, the device is hand-operated and does not employ any mechanism for metering the quantity of ink applied to the ribbon before such application. An example of such a device is found in U.S. Pat. No. 506,126, "Machine for Reinking Type Writer Ribbons," by J. M. Lowe.
Other examples of prior art re-inking apparatus are found in U.S. Pat. No. 3,731,649, "Ribbon-Inking Machine," by Frank R. Anderson and Albert J. Castro; and U.S. Pat. No. 3,885,518, "Ribbon-Inking Apparatus," by Anselm F. Varni. In addition, U.S. Pat. No. 2,956,300, "Web Tensioning and Cleaning Apparatus," by F. J. Bruno teaches a web tensioning and cleaning apparatus. None of these patents reveal that an apparatus capable of cleaning, re-inking, detecting holes in and aligning a printer ribbon.